Note: The risk of bias by domain corresponds to the highest risk of bias among outcomes by domain.
The overall risk of bias corresponds to the overall highest risk of bias assessed among outcomes.
| Bias | Author's judgement | Support for judgement |
| Randomization |
Some concerns |
Quote: "36 participants were randomized at 2:1 either to receive BV-01-B5 or V-01. Randomization was performed by an independent statistician using SAS statistical software version 9.4 or above. Random numbers were allocated to eligible participants in the order of enrollment. Participants received the investigational vaccines according to the randomization table."
Comment: Allocation sequence probably random. No information on allocation concealment |
| Deviations from intervention |
Low |
Quote: “open-label trial”
Deviations from intended intervention arising because of the study context: " Participants received the investigational vaccines according to the randomization table." No participant cross-over. Hence, deviations did not arise because of the trial context NEUTRALIZING ANTIBODY ASSAY GMT, nAb SEROCONVERSION RATE OMICRON, NEUTRALIZING ANTIBODY ASSAY GMT OMICRON Per-protocol analysis was performed on the immunogenicity outcomes. There were no exclusions in the analysis. As we are assessing the effect of assignment to intervention (intention-to-treat effect), we considered that the data were analyzed inappropriately. There was probably no substantial impact of failure to analyze participants according to their randomized assignment since there were no exclusions. Risk assessed to be low for the outcomes: Neutralizing antibody assay GMT. nAb Seroconversion rate Omicron. Neutralizing antibody assay GMT Omicron ADVERSE EVENTS, SERIOUS ADVERSE EVENTS Intention to treat analysis was performed in the safety outcomes As we are assessing the effect of assignment to intervention, the analysis method performed on these safety outcomes, was considered appropriate. Risk assessed to be low for the outcomes:Adverse events. Serious adverse events. |
| Missing outcome data |
Low |
Comment: 36 participants randomized; 36 participants analyzed.
Data available for all or nearly all participants randomized. Risk assessed to be low for the outcomes: Neutralizing antibody assay GMT. nAb Seroconversion rate Omicron. Neutralizing antibody assay GMT Omicron. Adverse events. Serious adverse events. |
| Measurement of the outcome |
Some concerns |
Comment: Method of measuring the outcome probably appropriate.
Measurement or ascertainment of outcome probably does not differ between groups. Unblinded study NEUTRALIZING ANTIBODY ASSAY GMT, nAb SEROCONVERSION RATE OMICRON, NEUTRALIZING ANTIBODY ASSAY GMT OMICRON Observer-reported outcome not involving judgement. Risk assessed to be low for the outcomes: Neutralizing antibody assay GMT. nAb Seroconversion rate Omicron. Neutralizing antibody assay GMT Omicron ADVERSE and SERIOUS ADVERSE EVENTS The authors reported on adverse events that may contain both clinically- and laboratory-detected events, which can be influenced by knowledge of the intervention assignment, but is not likely in the context of the pandemic. Risk assessed to be some concerns for the outcomes: Adverse events. Serious adverse events. |
| Selection of the reported results |
Some concerns |
Comment: the protocol and statisitical plan were not available. The retrospective registry was available (Dated October 19, 2022).
No information on whether the result was selected from multiple outcome measurements or analyses of the data. No information on whether the trial was analyzed as pre-specified. Risk assessed to be some concerns for the outcomes: Neutralizing antibody assay GMT. nAb Seroconversion rate Omicron. Neutralizing antibody assay GMT Omicron. Adverse events. Serious adverse events. |
| Overall risk of bias |
Some concerns |